本文選題：認(rèn)知無(wú)線電 + 頻譜檢測(cè)��； 參考：《寧夏大學(xué)》2016年碩士論文

【摘要】：最近幾年,信息化技術(shù)發(fā)展迅猛,人們對(duì)頻帶資源的需求度不斷攀升,有限的頻譜數(shù)量已不能滿足億萬(wàn)用戶及設(shè)備的需求。另外,提升匱乏頻帶的利用率也成了人們當(dāng)前亟待解決的難題。認(rèn)知無(wú)線電頻譜感知技術(shù)由于具有迅速、準(zhǔn)確檢測(cè)空閑頻譜的能力,成為提高頻譜利用率的一種新興手段。本文主要對(duì)頻譜感知的判決門限進(jìn)行了研究和改進(jìn)。首先對(duì)幾種傳統(tǒng)單用戶頻譜感知算法進(jìn)行闡述、對(duì)比,同時(shí),介紹了能夠緩解多徑、陰影以及終端隱蔽等現(xiàn)象的多用戶協(xié)作頻譜感知,該技術(shù)在彌補(bǔ)單用戶感知缺陷的同時(shí)也加大了網(wǎng)絡(luò)開銷。由于傳統(tǒng)算法大多根據(jù)虛警概率設(shè)置判決門限,使得門限無(wú)法適應(yīng)快速變化的通信環(huán)境。基于此,本文研究并改進(jìn)了兩種判決門限自適應(yīng)調(diào)整的頻譜感知優(yōu)化算法,并將其運(yùn)用于協(xié)作頻譜感知中,以減小協(xié)作用戶數(shù),降低網(wǎng)絡(luò)開銷,提高檢測(cè)性能。各認(rèn)知用戶根據(jù)感知信噪比的差異動(dòng)態(tài)調(diào)整門限閾值,更加實(shí)時(shí)有效地提升檢測(cè)精度。前一種算法通過(guò)計(jì)算單用戶和整個(gè)認(rèn)知網(wǎng)絡(luò)的最小錯(cuò)誤概率,得出對(duì)應(yīng)的門限值,并將檢測(cè)中授權(quán)用戶占用頻段和不占用頻段的概率及時(shí)間隨機(jī)化,使優(yōu)化算法更貼近于實(shí)際。后一種增強(qiáng)型自適應(yīng)門限感知算法利用檢測(cè)參數(shù)β對(duì)檢測(cè)概率和虛警概率所對(duì)應(yīng)的門限值進(jìn)行動(dòng)態(tài)調(diào)整,并對(duì)來(lái)自各方的授權(quán)信號(hào)進(jìn)行多次檢測(cè),選擇衰落最小的信號(hào)進(jìn)行判決,令判決結(jié)果更加可靠。
[Abstract]:In recent years, with the rapid development of information technology, the demand for frequency band resources is increasing, and the limited number of spectrum can no longer meet the needs of hundreds of millions of users and equipment. In addition, improving the efficiency of the scarce frequency band has become a difficult problem to be solved. Cognitive radio spectrum sensing technology has become a new method to improve spectrum efficiency because of its rapid and accurate ability to detect idle spectrum. In this paper, the decision threshold of spectrum sensing is studied and improved. Firstly, several traditional single-user spectrum sensing algorithms are described and compared. At the same time, multi-user cooperative spectrum sensing, which can alleviate the phenomena of multipath, shadow and terminal concealment, is introduced. This technique not only makes up for the defect of single user perception, but also increases the network overhead. Because most of the traditional algorithms set the decision threshold according to false alarm probability, the threshold can not adapt to the rapidly changing communication environment. In order to reduce the number of cooperative users, reduce the network overhead and improve the detection performance, two kinds of spectrum sensing optimization algorithms with adaptive adjustment of decision threshold are studied and improved in this paper. Each cognitive user dynamically adjusts the threshold threshold according to the difference of perceived SNR to improve the detection accuracy in real time and effectively. By calculating the minimum error probability of the single user and the whole cognitive network, the former algorithm obtains the corresponding threshold value, and randomizes the probability and time of the authorized user occupying and not occupying the frequency band in the detection, so that the optimization algorithm is closer to the reality. The latter adaptive threshold sensing algorithm dynamically adjusts the threshold values corresponding to the detection probability and false alarm probability by using the detection parameter 尾, and detects the authorization signals from all sides several times. Choosing the least fading signal to judge makes the result more reliable.
【學(xué)位授予單位】：寧夏大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2016
【分類號(hào)】：TN925

【參考文獻(xiàn)】

相關(guān)期刊論文 前1條

1 步如蘭;余豐;楊家瑋;;直接序列擴(kuò)頻中匹配濾波器的設(shè)計(jì)[J];空間電子技術(shù);2008年01期

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本文編號(hào)：1831508